8. Nanotechnology is new
It often comes as a surprise to learn that the Romans and Chinese were using nanoparticles thousands of years ago. Similarly, every time you light a match, fullerenes are produced. Degusssa have been producing carbon black, the substance that makes car tyres black and improves the wear resistance of the rubber, since the 1920s. Of course they were not aware that they were using nanotechnology, and as they had no control over particle size, or even any knowledge of the nanoscale they were not using nanotechnology as currently defined.
What is new about nanotechnology is our ability to not only see, and manipulate matter on the nanoscale, but our understanding of atomic scale interactions.
9. Building atom by atom
One of the defining moments in nanotechnology came in 1989 when Don Eigler used a SPM to spell out the letters IBM in xenon atoms. For the first time we could put atoms exactly where we wanted them, even if keeping them there at much above absolute zero proved to be a problem. While useful in aiding our understanding of the nanoworld, arranging atoms together one by one is unlikely to be of much use in industrial processes. Given that a Pentium 4 processor contains 42 million transistors, even simplifying the transistors to a cube of 100 atoms on each side would require 42 x 102operations, and that is before we start to consider the other material and devices needed in a functioning processor.
Of course we already have the ability to build things atom by atom, and on a very large scale; it is called physical chemistry, and has been in industrial use for over a century producing everything from nitrates to salt. To do this, we do not need any kind of tabletop assembler as in Star Trek, usually a few barrels of readily available precursor chemicals and maybe a catalyst are all that is required.
Compare this with the difficulty of producing anything organic atom by atom, a sausage for example. Everyone is familiar with the macroscale ingredients of a sausage, some meat, maybe some fat, cartilage or other kinds of tissue, even some bone, all encased in animal gut. Never mind, argue the proponents of assemblers, things are simpler at smaller scales.
Zooming down to the microscale we still have far more complexity than we would like to attempt to replicate, with cells, cytoplasm, mitochondria, chromosomes, ribosomes and many other highly complex items of natural engineering. Moving closer to the nanoscale, we still have to deal with nucleic acids, nucleotides, peptides and proteins, none of which we fully understand, or expect to even have the computing power to understand in the near future.
In terms of return on our investment, a farmyard containing a few pigs is a far more effective sausage machine than we could ever design, and has several other by-products such as hams and a highly effective waste disposal system. This serves to illustrate just how far we are away from being able to replicate nature.
10. Attack of the killer nanobots
In terms of capturing the public imagination, unleashing hordes of self-replicating devices that escape from the lab and attack anything in their path is always going to be popular. Unfortunately nature has already beaten us to it, by several hundred million years. Naturally occurring nanomachines, that can not only replicate and mutate as they do so in order to avoid our best attempts at eradication, but can also escape their hosts and travel with alarming ease through the atmosphere. No wonder that viruses are the most successful living organisms on the planet, with most of their `machinery' being well into the nano realm. However, there are finite limits to the spread of such `nanobots', usually determined by their ability, or lack thereof, of converting a sufficiently wide range of material needed for future expansion. Indeed, the immune systems of many species, while unable to completely neutralize viruses without side effects such as runny noses, are so effective in dealing with this type of threat as a result of the wide range of different technologies available to a large complex organism when confronted with a single purpose nano-sized one. For any threat from the nano world to become a danger, it would have to include far more intelligence and flexibility than we could possibly design into it.
Our understanding of genomics and proteomics is primitive compared with that of nature, and is likely to remain that way for the foreseeable future. For anyone determined to worry about nanoscale threats to humanity should consider mutations in viruses such as HIV that would allow transmission via mosquitoes, or deadlier versions of the influenza virus, which deserve far more concern than anything nanotechnology may produce.